Listen and accept function
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A socket is an interface between the application layer and transport layer within a host. It allows for identification through a hostel name + room number or IP address + port number. The listen() function converts a socket to a passive socket and specifies the maximum number of connections the kernel should queue in incomplete and complete connection queues. Accept() retrieves completed connections from the completed connection queue.
Listen and accept function
- 1. What is a socket ? It is an interface between application layer and transport layer within a host. CNP Seminar by Jithin P 2
- 2. Application Layer Transport Layer Socket CNP Seminar by Jithin P 3
- 3. Why socket ? Kannadasan Yamuna For Identification ? CNP Seminar by Jithin P 4
- 4. Why socket ? Hostel Name + Room No IP address + Port number Socket CNP Seminar by Jithin P 5
- 5. listen() accept() CNP Seminar by Jithin P 6
- 6. listen() Called only by TCP server Performs two actions Convert the socket in to passive socket Specify the maximum number of connections the kernel should queue CNP Seminar by Jithin P 8
- 7. For a listening socket the kernel maintains two queues An incomplete connection queue Waiting for 3-way handshake A complete connection queue Completed 3-way handshake CNP Seminar by Jithin P 9
- 8. 3-way handshaking client server Connect called Create entry on incomplete queue Connect returns Entry moved from incomplete queue to complete queue CNP Seminar by Jithin P 10
- 9. int listen(int sockfd, int backlog) CNP Seminar by Jithin P 11
- 10. Questions ? What is the default size of backlog ? Which queue is longest one (complete/incomplete) ? What will happen when queue is full ? CNP Seminar by Jithin P 12
- 11. accept() Completed connection queue Incomplete connection queue Arriving SYN CNP Seminar by Jithin P 13
- 12. accept() int accept(int sockfd, socket addr, socket addrlen) If success return a brand new descriptor ie descriptor of connected socket. CNP Seminar by Jithin P 14
- 13. References Unix Network Programming W.Richard Stevens Computer Networking a top down approach James F Kurose Wikipedia pubs.opengroup.org CNP Seminar by Jithin P 15
- 14. Questions CNP Seminar by Jithin P 16